Combine all the marinade ingredients together in a bowl.,Mix well.,Cut the chicken into desired sizes (rough dice), place in a large bowl and pour over the marinade.,Cover and leave to stand for about 30 minutes in a fridge.,For the curry sauce: peel and roughly chop the onions, crush the ginger and garlic together, wash and roughly chop the tomatoes.,Make a masala paste by combining the garam masala, turmeric and chilli powder in a small bowl with a little water to make a thin paste.,Heat the oil in a heavy-based saucepan.,______,Add the ginger/garlic paste and cook for further 1-2 minutes stirring constantly to prevent sticking at the bottom of the pan.,Add the masala mixture, bay leaves and cook for few seconds.,Then add the tomato puree and chopped tomatoes.,Simmer gently for about 30-40 minutes - a little water may be added at this point to give the right consistency.,The sauce is now ready for use.,Keep it warm in a pan.,Heat the oil in a frying pan to smoky hot and shallow fry the chicken in small batches to seal the meat.,Remove with a slotted spoon and add to the curry sauce.,Continue until all meat is fried.,Bring the curry to the boil, then add some shopped coriander and spring onions and chilli.,Simmer gently until the meat is cooked.,Remove any access grease from the sauce; adjust the consistency with corn flour mixed in water.,Serve sprinkle with coriander and spring onions.